In vitro production of peroxynitrite by haemocytes from marine bivalves: C-ELISA determination of 3-nitrotyrosine level in plasma proteins from Mytilus galloprovincialis and Crassostrea gigas.

Peroxynitrite is increasingly proposed as a contributor to defence system in marine bivalve. It can be formed by combination of superoxide and nitric oxide, and can react with tyrosine residues of proteins giving rise to 3-nitrotyrosine. The present article describes a competitive ELISA for the measurement of 3-nitrotyrosine contents of plasma proteins from marine bivalves by means of a monoclonal anti 3-nitrotyrosine antibody mouse IgG. This assay is sensitive enough to determine the amounts of 3-nitrotyrosine in plasma proteins from one animal only. Using the C-ELISA, we have shown that the phagocytosis of zymosan particles increased the 3-nitrotyrosine levels of plasma proteins from mussel M. galloprovincialis and oyster C. gigas 5.8 and 7.5 times respectively.